1. Field of the Invention PA1 providing a feed containing at least 10 vol % n-butenes; and PA1 contacting said feed with silicalite at a temperature of at least about 300.degree. C. in the presence of steam in a water/feed molar ratio of about 0.5-5. However that process provides reaction products containing water. Further, that process produces excessive amounts of liquid by-products. Also, it has been observed that deactivation of the silicalite is excessive for the process to be industrially applicable. PA1 passing steam, either pure or diluted in an inert gas, over silicalite at a temperature of from 300 to 750.degree. C.; PA1 providing a feed containing (i) at least 10 vol % of n-butene and (ii) isobutene if any in an isobutene:n-butene ratio of maximum 1:2; PA1 passing said feed over said silicalite at a temperature of at least 500 C.; and PA1 recovering a stream containing an increased amount of isobutene.
The present invention relates to the isomerization of olefins. More particularly, it relates to an improvement in a process for the isomerization of olefins over silicalite.
2. Description of Prior Art
U.S. Pat. No. 4,587,375 discloses a process for the isomerization of n-butenes comprising:
There is thus a need in art for an improvement of the existing isomerization processes of olefins over silicalite.